- name
- nodejs-patterns
- description
- Async control flow, error handling, module design, streams, and production hardening
- metadata
- {"author":"cosmicstack-labs","version":"1.0.0","category":"backend","tags":["nodejs","backend","javascript","async","server"]}
# Node.js Patterns
Production-grade Node.js backend patterns.
## Async Patterns
### Prefer Async/Await
```javascript
// Good
async function getUser(id) {
const user = await db.findUser(id);
return user;
}
// Avoid raw callbacks or.then() chains
```
### Parallel Execution
```javascript
// Sequential (slow)
const user = await fetchUser(id);
const posts = await fetchPosts(id);
// Parallel (fast)
const [user, posts] = await Promise.all([
fetchUser(id),
fetchPosts(id),
]);
```
## Error Handling
### Global Handler
```javascript
process.on('uncaughtException', (err) => {
console.error('Uncaught:', err);
// Graceful shutdown
server.close(() => process.exit(1));
});
process.on('unhandledRejection', (reason) => {
console.error('Unhandled Rejection:', reason);
});
```
### Express Error Middleware
```javascript
app.use((err, req, res, next) => {
const status = err.status || 500;
res.status(status).json({
error: err.message,
...(process.env.NODE_ENV === 'development' && { stack: err.stack }),
});
});
```
## Module Design
- Single responsibility per module
- Export a class or factory function, not plain objects
- Use dependency injection for testability
- Prefer CommonJS (require) or ESM (import), consistent throughout
## Production Hardening
- Cluster mode for multi-core
- Process manager (PM2) with auto-restart
- Health check endpoints
- Graceful shutdown (SIGTERM handler)
- Memory limit monitoring
- Structured logging (pino/winston)
عرض على GitHub